Hand calculators



R. E. MELENDEZ May 12, 1970 HAND CALCULATORS 2 Sheets-Sheet 1 Filed May 13 1968 FIG.5

FIG.|

PIC-3.4

FIG.5

INVENTOR.

RALPH E. M Zf/VDEZ M ATTORNEY FIG.7

y 1970 R. E. MELENDEZ 3,511,438

HAND CALCULATORS Filed May 15, 1968 2 Sheets-Sheet 2 INVENTOR. IZALPH E. MEIENDEZ A Tron/v5 Y United States Patent 3,511,438 HAND CALCULATORS Ralph E. Melendez, 63 Margaret Road, North Massapequa, N.Y. 11758 Filed May 13, 1968, Ser. No. 728,404 Int. Cl. G06c 27/00 U.S. Cl. 235-78 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a fractional hand calculator which provides the function of adding and subtracting fractions as well as the conversion of fractions to decimaled numbers. Further in the adding and subtracting feature provision is made for the indication of whole numbers over the number one. This is accomplished by providing a first disc and a second disc, the first disc being rotatable about a fixed center point. The second disc which is fixed in position is provided with a window therein to permit the display of whole numbers as a result of a gear arrangement which is rotatably disposed between the first and second discs.

Heretofore it has been known in the prior art that numerous calculating devices have been marketed. The majority ofthese calculating devices have been rather cumbersome and difficult to interpret as well as difiicult to manipulate.

Further, in almost every instance each fractional hand calculator presently marketed has had the drawback of not indicating a whole interger thereby forcing the user to guess at a value of whole number while having the fractions readily available to him.

It is the object of the present invention to avoid and overcome the foregoing and their difficulties in the prior art devices by providing a fractional hand calculator which is easily operable as well as inexpensive.

Another object of the present invention is to provide a fractional hand calculator which will indicate whole numbers after fractions have been added in excess of a fractional total.

A further object of the present invention is to provide a fractional hand calculator having available readily readable totals, fractions and decimal figures.

For a better understanding of the present invention reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the respective views and wherein:

FIG. 1 is a plan view of the second disc,

FIG. 2 is a cross-sectional view of the second disc, with the gear and knob arrangement mounted,

FIG. 3 is a plan view of the bottom of the second disc showing the disposition of the gear arrangement,

FIG. 4 is a plan view of the gear,

FIG. 5 is a cross-sectional view of the gear, and knob control,

FIG. 6 is a plan view of the first disc,

FIG. 7 is a cross-sectional view of the first disc,

FIG. 8 is a plan view of the third disc or base plate,

FIG. 9 is a cross-sectional view of the third disc, or 'base plate, and

FIG. 10 is a plan view of the fractional hand calculator fully assembled.

Referring now to FIGS. 1, 3 and 6, a base plate 10 as shown in FIG. 8 is provided with a circular raised portion 11 around which the first disc 12 may be rotatably mounted. A second disc 14 may be fixedly mounted over said first disc 12 as by screws connecting the second disc 14 to the raised portion 11 without interferring with the rotational movement of the first disc 12 and permitting relative motion between said first disc 12 and said second disc 14. As shown in FIG. 1 a series of fractions are indicated around the outer periphery 16 of the second disc 14 and adjacent to each fractional number there is provided its decimal equivalent to six figures. The second disc 14 may be provided with a window 18 disposed radially inwardly of the periphery outer 16 and is adapted to indicate whole numbers as hereinafter described.

As shown in FIG. 6 the first disc 12 may be provided with a series of holes 20 along its outer eriphery 22 such that by utilizing a pointed member 46 (FIG. 10) the first disc 12 may be forced to rotate.

The first disc 12 may be provided as shown in FIG. 6 with a series of fractional numbers disposed radially inwardly of its outer periphery 22 from 1-64 to 63-64 and each of the numbers may be in alignment with a slot 24 provided in the second disc 14 so that when the first disc 12 is rotated the numbers may appear clearly in the slot 24 provided in the second disc 14.

Beneath the second disc 14 and rotatably connected to its bottom surface there may be provided a gear arrangement 26, shown in FIG. 3, which is adapted to rotate in accordance with the movement of the first disc 12 relative to the second disc 14.

The gear arrangement 26 may provide an addition of fractional numbers and converts the same to at least one whole number, in the manner hereinafter described.

In order to provide a means of indicating a whole number after the addition of two fractions, a gear-like member 28 may be rotatably connected to the bottom surface 30 of the second disc 14. The gear-like member may be provided with a plurality of points along its outer edge. Each point may have associated therewith a whole number which is disposed, prominently, on its upper surface and which is in alignment with the window 18 in the second disc 14. On each of the points 32 of the gear-like member 28 there may be provided a raised portion 34 which is adapted to releasa-bly lock in at least one of a series of depressions 36 which is provided on the bottom surface 30 of the second disc 14 so that the gearlike member will not skip on turning. In order to rotate the gear-like member 28, and thereby change the whole number appearing in the window 18, a protruberance 38 may be provided on the upper surface of the first disc 12, and may be in rotative alignment with the tips of the points 32 on the gear-like member 28. As the first disc 12 makes a complete clockwise revolution in its adding cycle, theprotruberance 38 may contact a point 32 of the gear-like member 28 and rotate the same sufficiently to change the whole number appearing in the window 18 by one higher digit or integer. Thus, when adding fractions and the first disc 12 makes one complete clockwise revo lution the gear-like member 28 will be moved just enough to change the whole number designation so that the raised portion 34 on the gear-like member 28 will register in one of the series of depressions 36. Attached to the gear-like member 28 is a knob arrangement 40 which includes a knurled member and stem, the stem 40 protruding through the second disc 14. The knob arrangement 40 may be adapted to change the whole number designation appearing in the window 18 when or after each calculation. The knob 40 may be resiliently held in position by means of a spring 42, however, other resilient means may be used to accomplish this purpose.

As shown in FIG. 8 the outer peripheral surface of the base plate 10 may have numerical designations thereon which are used in the subtraction of numbers rather than the adding cycle as previously described.

In operation the fractional hand calculator 10 functions with the use of a pointed member 46 which use will be more fully described in the following description of the operation of the calculator. The fractional numbers appearing on the second disc 14 are to be used solely for the addition operation. When two fractions are to be added and the calculator is cleared, the pointed member 46 is inserted in the hole 20 on the rotatable first disc 12 adjacent to the fractional number to be added. The hole will accept the pointed member in the second disc such that the second disc is rotated in a clockwise direction until the member 46 strikes the dial stop 48 on the second disc 14. The fraction to be added is done in a similar manner in that the pointed member is placed in the hole adjacent to the fractional number to be added and the rotatable first disc 12 is rotated in a clockwise direction and at the conclusion of the rotation of this disc the summation of the added fractions will appear in the window. In the event that the fractions added together involve a whole number the whole number will appear in the window 18 in the second disc 14.

The subtraction operation is performed in this similar manner as to the additional cycle with the exception that the fractional designations shown on the outer periphery of the base plate are to be used for this operation only. Utilizing these fractional numbers on the base plate 10 the pointed member 46 is inserted in the hole 20 adjacent to the fraction to be subtracted on the rotatable first disc 12, providing that a accumulative total of fractions to be subtracted is less than the total of fractions shown in the window 18 on the second disc 14 at any one time. By means of the pointed member 46 the second disc is rotated in a counterclockwise direction until the member 46 strikes the dial stop 48 the result will appear in the window and slot provided in the second disc 14.

It should be noted that when a fractional number greater than the number one is to be substracted the knob 40 may be rotated so that a manual and mental approximate subtraction to the nearest whole integer may be obtained and will appear in the window 18.

In accordance with the patent statutes a preferred embodiment has been described in detail, however, it should be particularly understood that the invention is not limited thereto or thereby.

I claim:

1. A fractional hand calculator comprising a base plate having an outer periphery, a first disc rotatably mounted on said base plate and having a multiplicity of holes around its outer periphery and is provided with fractional indicia disposed inwardly of said outer periphery, a second disc fixedly mounted over said first disc and being provided with fractional indicia around its outer periphery, said second disc being provided with a dial stop, a window disposed in said second disc, a gear means rotatably disposed beneath said second and first disc, said gear means having whole number indicia provided thereon and second disc overlying said indicia on said first disc where the sum of two (2) added fractions will appear, whereby a pointed member is inserted in said holes around the outer periphery of said second disc to rotate the same such that two (2) fractions are added permitting the display of a whole number in said window.

2. A fractional hand calculator according to claim 1 wherein a knob is rotatably connected through said second disc and is in communication with said gear arrangement for manually resetting the whole numbers aftereach addition. 1 1

3. A fractional hand calculator according to claim 2 wherein said gear arrangement comprises agear-like memher being provided with a' multiplicity of points, and a raised portion disposed on each point and facing the bottom surface of said second disc, a hole number associated with each of said multiplicity of points, each number being rotatably alignable with said window in said second disc.

adapted to cooperate with said first disc to provide a whole number in alignment with said window, a slot in said 4. A fractional hand calculator according to claim 3 wherein said second disc being provided with a protruberance adapted to engage one of said points on said gearlike member for rotating said gear-like member when two (2) fractions to be added create more than a fractional amount.

5. A fractional hand calculator according to claim 4 wherein said bottom surface of said second disc is provided with a series of depressions, said raised portions on said points of said gear-like member adapted to releasably lock within said series of depressions to prevent skipping of said gear-like member when said gear-like member is rotated.

6. A fractional hand calculator according to claim 5 wherein said knob and said gear-like member is spring loaded in said second disc.

7. A fractional hand calculator according to claim 1 wherein the base plate is provided with fractional indicia along the outer periphery thereof, said indicia are employed in subtracting one (1) fractional number from another fractional number.

References Cited UNITED STATES PATENTS 510,927 12/1893 Neal 235-78 X 1,188,108 6/1916 Smith 235--78 1,336,990 4/1920 Swenson 23583 1,498,309 6/1924 Smith 235-78 2,237,873 4/ 1941 Barok 235--7-8 3,002,682 10/ 1961 Scholtens 235-78 FOREIGN PATENTS 504,276 4/1939 Great Britain.

RICHARD B. WILKINSON, Primary Examiner S. A. WAL, Assistant Examiner 

